Objective measurement of performance during acute stress in patients with essential hypertension: assessment of the effects of propranolol and metoprolol.

1. A standardized method of objectively measuring performance during simulated car driving is described. 2. The effect of a single dose of propranolol and metoprolol were compared with placebo in two groups of patients with untreated essential hypertension. 3. Performance was similar after beta-adrenoreceptor-blocking agents or placebo. 4. Blood pressure response to stress persisted after administration of the blocking agents.